Distributor construction



Jan. 7, 1947. w. L. CARLSON DISTRIBUTOR CONSTRUCTION Filed June 26, 1944 3nventora Ka /51171? (Zr/3022 9L attorney Patented Jan. 7, 1947 DISTRIBUTOR CONSTRUCTION Wilbur L. Carlson, Rochester, N. Y., assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application June 26, 1944, Serial No. 542,138

7 Claims.

This invention relates generally to the construction of distributors and more particularly to certain features of construction which are of general use but especially desirable for use in magneto units adapted for airplane engine ignition systems.

One of the objects of the invention is to provide a distributor which is of simple and compact construction having only a relatively few parts which can be readily manufactured and assembled.

A further object is to provide a distributor embodying a rotor with main running brushes and supplemental brushes aiiording a retarded spark on starting which is so constructed that the parts can be assembled in either of two positions to operate in either direction of rotation.

A still further object is to provide a construction of the distributor which is particularly adapted for use in magneto units for airplane engine ignition systems to insure the proper spark distribution with freedom from electrical breakdowns on operation at relatively high altitudes.

Other objects and the several advantages of the present invention will be set forth or will be aparent from the followin description of the embodiment illustrated in the accompanying drawing, in which:

Fig. 1 is a fragmentary side elevation of a magneto unit with parts broken away and parts of the distributor in substantially vertical section.

Fig. 2 is a fragmentary front elevation with parts broken away and parts in section.

Fig. 3 is a fragmentary front elevation of the distributor rotor assembly showing an alternative relative location of the brushes.

Fig. 4 is an enlarged perspective view of the main distributor arm.

Referring first to the showing in Fig. 1, only those parts which are essential to an understanding of the features of construction of the present invention have been illustrated in detail and those parts not so illustrated may be of any desired conventional construction.

Although the present distributor construction may be otherwise employed, it has been diagrammatically indicated as associated with or forming a part of an inductor type magneto unit having a casing indicated at 6 which may house a generator, induction coil and interrupter mechanism of conventional construction.

Th distributor is also preferably, although not necessarily, located within a completely sealed and insulated chamber indicated generally at 8 and is similar in this respect and in certain other features to be noted hereinafter to the construc- 2 tion which is the subject of my application Serial No. 405,743, filed August 7, 1941, of which the present application is a continuation-in-part.

The distributor chamber 8 is formed by the housing I and cover 12 of molded insulation material such as Bakelite with spaced distributor contacts consisting of metal inserts molded in the housing It. These contacts are arranged, as is also shown in my above-identified prior application. in two parallel arcuate rows in spaced transverse planes in the upper half of the distributor chamber. The inner row of contacts is designated at 14 and the outer row of contacts at it and bores I 8 extend from the upper face of the housing ill to the contacts to receive the separate conductors adapted to connect the contacts to the respective spark plugs of the engine.

The cover [2 is secured to and closes the front end of the housing It] and is shown as having inserts molded therein including a contact portion 25) and a plate portion 22 with a bore 24 leading to the plate portion to receive a conductor adapted to be connected to a booster magneto or other external current source to furnish ignition current for starting purposes.

A distributor shaft 26 extends through the inner wall of the housing In and is mounted to rotate by means of the spaced ball bearings 28 on a sleeve 30 which is preferably molded as an insert in the housing In. As is disclosed in my application Serial No. 405,743, the distributor shaft 26 is adapted to be electrically connected with the terminal of the high tension winding of the usual induction coil and is adapted to be rotated by a drive gear 32 of insulating material which meshes with a gear 34 mounted on the usual magneto rotor shaft.

As is also disclosed in my prior application, a shaft sealing means is preferably provided adjacent the outer end of the distributor shaft 26 to prevent the entrance of external air to the distributor chamber 8. This feature does not constitute an essential part of the present invention but is mentioned because of the showing herein of sealing means for the several contacts I4 and IE. Even through these contacts are molded in the housing I0 there is no assurance that the molding material around the contacts will form a gas-tight joint and it has been found desirable to insure against any chance of leakage by providing washers 36 of flexible material such as rubber around the exposed terminals of the contacts in the bores It? with metal washers 38 having wedge or V-shaped lower faces which force the flexible washers 36 into tight engagement with opposite sides thereof to receive a pair of bolts I 46 to secure the distributor arms or brushes to rotate with the distributor shaft. Y

The main distributor arm 43 is shown in detail in Fig. 4 as consisting of a metal-plate having a flat portion 58 with a central opening to receivea forwardly projecting portion of the bearing housing 40 and with diametrically opposite arcuate holes 52 to receive the securing bolts 45, and relatively narrow portions 54 and 56 which extend outwardly in substantially radial directions from the flat portion 50 andare bent axially to form V the diametricallyopposite running brushes 58 and to which are. located at opposite sides of the plane of the flat portion to rotate in theispaced transverse planes of the rows of contacts it and i6 as will be hereinafter described.

The supplemental distributor arm, generallyat 62, is shown as formed or molded insulation material having centrally located ears 64 extending transversely on opposite, sides of the arm 52 with openings to receive the securing bolts id and having inserts molded therein including an axiallyextending contact portion E5 and aidiametrically extending portion 58. The opposite ends of theportion B3 are exposed to indicated less of the direction of rotation in any particular installation.

The distributor arms as and 62 are shown in Figs. 1 and 2 as assembled for right-hand or clockwise rotation indicated by the arrow in Fig, 2. The fiat portion 5. 3 of arm 68 is clamped between the bearing housing 35 and arm 62 by the bolts '35 in such a position that the running brush 58 is located in the same transverse plane as the starting brush it and spaced circumferentially ahead of the brush ill so that the brushes constitute the starting brushes ill and i2 which are diametrically opposed but o'ifsetaxially so that the brush ll! rotates in the transverse plane of the row of contacts Hi while the brush l2 rotates in the transverse plane of the'row of contacts 16. The front end =01 the contact portion 66 is exposed and adapted to be only slightly spaced from the contact portionZfl in cover NZ to conduct the starting-current to the brushes ill and '12.

-As shown in Fig. -2, the diametrically-opposite St brushes it and 12' of arm 62 are in an axial or longitudinal plane at right angles to a plane through the-center ofv the ears i4 and securing bolts-J16 whereas the portions 54 and 5o 7 of arm 4 3=are"angu1arly offsetwith reference to .these planes to position the diametrically opposite running brusheslid and fill inxcircurnferentially spaced relation to the-brushes ill and '52. This relationship is suchas to'obtain the desired degree of retardation of the ignition when usin the starting brushes in accordance with conventional practiceand is subject to a slight adjustment afforded by the arcuate elongation of the openings 52 in thearm d8.

It was heretofore stated that one of theobjeots of the present invention is to provide a distributor embodying a rotor with main running brushes and supplemental bruShesaffoiding-a retarded spark on starting which is so'constructed that the parts can be assembled in either of two positions to operate inzeither direction of rotation. Although designed particularly for use in dual ignition systems for air-plane engines wherein a magneto unit is mounted on each sideof the engine with drive connections to rotate the respective distributor rotors and other rotating parts of the units in opposite directions, it will be apparent that this feature is. also desirable in'the construction of distributors for more general use so that the same par-tsmay be: employed for original installation and service replacementsregardferentially spaced on either ei-Z and I 3 rotate in th plane of contacts and starting brush it are a similar relative ition to rotate in the transverse plane of the in the tributor arms and '22 are shown as assembled for left-hand or counterclockwise rotation. In this position the arm 5?. is assembled in the same manner as in Figs. 1. and 2 but the main :F'st butor arm has been t rned over or reversed so that the running brush is located in the some transverse plane as the st rting brush it. and the running brush 5% is lo in the transverse plane as the starting brush ill with the running brushes spaced circumferentially ah of the starting bru hes in the direction of rotation indicated he arrow. The brushes and "iii rotate in the plane of contacts it and the diametrically opposite brushes'eil and i2 respectively, rotate in the of contacts it.

On reference to the dra.

i will be apparent that the two relativ positi 1 rting and ill" 'er rotation in oi oi the o pritributor rily portions and of plane of the flat central porti the brushes and in parallel planes spaced from the plane or" the portion and spaced from one another a distance equal the center line distance between the rows 0 ntacts i l and and in both positions of the fiat portion of arm i clamped b he arm i2 and bearing housing it with t' tion in a transverse plane. midway between the transverse planes of contacts i and it will be understood that ory a single embo iment of the present invention has shown described herein and other embodiments and many modiii ations will be obvious to those skilled in the art without departing from the spirit or .scope of the invention as defined by the claims appended hereto.

I claim:

1. In a distributor, the combination with a plurality of fixed spaced contacts arranged in rows in spaced parallel planes, of .a distributor rotor including a main distributor arm withdiametrically opposite running brushes and a supplemental arm with diametrically opposite starting brushes with te opposite of eacharm arranged respectively in the spaced planes of said rows of cont ets, means said arms may be assembled in either of two relative posi tions wherein the running brushes ar one side or the other side of the starting brushes.

2. In a distributor, the combination with a plurality of fixed sp ced contacts arranged in rows in spaced parallel planes, of a distributor-"rotor circum-' including a main distributor arm with diametrically opposite running brushes and a supplemental arm with diametrically opposite starting brushes with the opposite brushes of each arm arm arranged respectively in the spaced planes of said rows of contacts, said main distributor arm being so formed that it may be mounted in either of two positions relative to said supplemental arm to selectively space said running brushes circumferentially on either side of said starting brushes.

3. In a distributor, the combination with a plurality of fixed spaced contacts arranged in rows in spaced parallel planes, of a main distributor arm comprising a metal plate with diametrically opposite running brushes, a supplemental arm comprising a member of insulatin material with a metal insert providing diametrically opposite starting brushes, the opposite brushes of each arm being arranged respectively in the spaced planes of said rows of contacts, and means to secure said arms together with each running brush adjacent to and circumferentially spaced on one side of the respective startin brush that is in the same plane.

4. The combination set forth in claim 3 in which said main distributor arm is symmetrically formed whereby the same may be reversed relative to said supplemental arm to dispose the respective runnin brushes thereof on the other side of the adjacent starting brushes,

5. In a distributor, the combination with a plurality of fixed spaced contact arranged in rows in spaced transverse planes, of a rotatable distributor shaft, a distributor arm comprising a metal plate with integral diametrically extending portions which terminate in axially spaced brushes, and means to secure said arm to said shaft and position each of said brushes to rotate in the plane of one of said rows of contacts.

6. In a distributor, the combination with a plurality of fixed spaced contacts arranged in rows in spaced transverse planes, of a rotatable distributor shaft, a distributor arm having diametrically opposite brushes in axially paced relation, and means to secure said arm to said shaft with said brushes respectively in the spaced planes of said rows of contacts, said brushes bein symmetrically arranged with reference to said arm whereby said arm can be bodily reversed in position and said brushes will still be arranged in the spaced planes of said rows of contacts.

7. In a distributor, a rotatable distributor shaft, a bearing for mounting said shaft including a bearing housing secured to one end of said shaft, a main distributor arm comprising a metal plate With diametrically opposite running brushes, a supplemental arm comprising a member of insulating material with a metal insert providing diametrically opposite starting brushes, and means to secure said supplemental arm to said bearing housing and clamp said main distributor arm between said supplemental arm and bearing housing.

WILBUR L. CARLSON. 

